Oil-stone.



Patented Dec. I8, I900.

M. B. HILL.

DI L S T 0 N E.

(Application filed Feb. 5, 1900.)

(No Model.)

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' UNITED STATES PATENT OFFICE.

MlLTON B. HILL, OF WORCESTER, MASSACHUSETTS, ASSIGNOR TO THE NORTON EMERY WHEEL COMPANY, OF SAME PLACE.

OIL-STON E.

SPECIFICATION formingpart of Letters Patent No. 664,319, dated December 18, 1900.

Application filed February 5; 1900' Serial 48- (No model.)

To all whom, it may concern.-

Be it known that I, MILTON B HILL, a citizen of the United States of America, and a resident of the city and county of Worcester, in the Commonwealth of Massachusetts, have invented certain new and useful Improvements in Oil-Stones, of which the following is a specification.

My invention relates to oil or whet stones, particularly to artificial stones manufactured from emery or corundum; and one object of my invention is to provide an artificial stone on which the oil or other lubricant used with it will remain on the abrasive surface thereof without being quickly absorbed into the stone.

Other objects of my invention, resulting in a superior stone, one requiring little oil in its use, and any further objects attained therev by will appear from a complete understandpose.

ing of the invention as described below.

.In the use of oil-stones for grinding tools and the like it is customary to apply some lubricant, as oil or water, to the surface of the stone to keep it free from small particles of the material ground and to improve and preserve its cutting qualities and operation. In natural oil-stones, such as the well-known Arkansas stone and others, the formation or structure of the mass of material of which the stone is composed is of such a compact nature that the oil or water used on it does not readily absorb into the stone, but remains on the surface,where it is needed to serve its pur- This desirable feature makes only a small quantity of oil necessary and does not require frequent applications; In artificial stones, however, particularly those made by the vitrified process, the mass of material of which they are composed is quite open and porous. Consequently such stones take up readily a considerable quantity of liquid, absorbing it by capillary attraction into the mass of the stone, so that it does not remain on the surface, where it is needed and used. Even when the stone has been allowed to soak for a long time in oil at ordinary temperatures the difficultyis only partially avoided. To fill the stone for the first timerequires a considerable quantity of oil, and owing to its porous nature the oil evaporates and tends to gradually seep out into the packages or holders in which the stone is contained, injuring them and requiring further and frequent applications.

My invention consists of providing an oilstone with a filler of such a character that the disadvantages of a porous stone, referred to above, will be obviated, while its advantages, which it is not necessary to set forth here, will be preserved.

In the drawings, Figure l is a perspective View of an oil-stone of ordinary shape. Fig. 2 is a section of said stone broken open and showing a portion thereof magnified.

The figures are intended to illustrate an oilstone of a kind to which my invention would apply. By the process known as the vitrified process the mass of material is subjected to intense heat, which melts the bond mixed with the particles of abrasive substance in said mass and holds them together in a fixed mass which appears to the eye as one solid imporous body. Upon examination, however, it will be found that the texture of the mass is quite porous and open.

Referring to Fig. 2 in the magnified portion shown within the circle of the objective 0, the solid particles of the abrasive and the bond (which for the purpose of this description it is not necessary to distinguish apart) are denoted by a and the spaces or pores by b.

That these spaces may not clog up with small particles of steel, which would interfere with the cutting properties of the stone, and also for the purpose of making smoother work some lubricant is desirable on the grindingsurface, and as an application of oil on the surface of a stone of the character described does not serve the purpose, for the reasons above set forth, these pores are filled in accordance with my invention with some substance which at ordinary temperature is-solid or semisolid and which will not interfere with the cutting or grinding properties of the stone. The stones are therefore soaked in melted wax, paraffin, petrolatum, or any substance having the properties of the abovenamed materials adapted for this purpose until the pores are thoroughly filled with the melted substance. The stones are then withdrawn and allowed to cool, and the result is that the pores are filled with a solid or semivent any oil whatever from being absorbed.

It does, however, prevent the disadvantages noted above when the stone is used without a filler.

What I claim, therefore, as my invention,

and desire to secure by Letters Patent, is-

1. In an oil-stone the combination with particles of abrasive material, of a vitrified, waterproof bond adapted to hold said particles together in a fixed mass,and a soft filler adapt ed to fill the spaces or pores between said particles consisting of a solid or semisolid mass of material at ordinary temperatures, which is liquid when heated, substantially as described.

2. In an artificial oil-stone the combination with particles of abrasive material, of a hard, vitrified, insoluble bond adapted to hold said particles together in a fixed mass, and a filler consisting of petrolatum adapted to fill the spaces or pores between said particles, whereby an undue absorption of oil used on said stone is prevented, substantially as described.

Signed by me at Worcester, Massachusetts, this 30th day January, 1900.

' 1 MILTON B. HILL.

Witnesses:

JOHN S. GOULD, ALDUS C. HIGGINS. 

